Oxygen transfer in a full-depth biological aerated filter

The City of San Diego, California, evaluated the performance capabilities of biological aerated filters (BAFs) at the Point Loma Wastewater Treatment Plant. The City conducted a 1-year pilot-plant evaluation of BAF technology supplied by two BAF manufacturers. This paper reports on the first independent oxygen-transfer test of BAFs at full depth using the offgas method. The tests showed process-water oxygen-transfer efficiencies of 1.6 to 5.8%/m (0.5 to 1.8%/ft) and 3.9 to 7.9%/m (1.2 to 2.4%/ft) for the two different pilot plants, at their nominal design conditions. Mass balances using chemical oxygen demand and dissolved organic carbon corroborated the transfer rates. Rates are higher than expected from fine-pore diffusers for similar process conditions and depths and clean-water conditions for the same column and are mostly attributed to extended bubble retention time resulting from interactions with the media and biofilm.     

Campylobacter coli infection causing second trimester intrauterine growth restriction (IUGR): a case report and review of the literature

Campylobacter is a gram-negative, microaerophilic, curved rod and a normal resident of the gastrointestinal flora and may be the cause of disease in animals. Transmission to humans occurs by ingestion of contaminated food or by direct contact with infected animals. In the past few decades, an increasing number of reports have implicated the presence of this organism in human abortions as well. An infectious mechanism due to primary placental inflammatory damage followed by secondary damage to the fetus following placental insufficiency and ischemia was suggested. The most common species of Campylobacter are Campylobacter jejuni and Campylobacter coli, which are classically associated with enteritis in humans. We present a rare case of mid-gestation intrauterine growth restriction (IUGR) associated with maternal bacteremia caused by C. coli infection. Our literature review focuses on Campylobacter infections occurring in the second and third trimesters of pregnancy. In all cases, mild maternal symptoms consisting of fever and weakness were presented. However, associated adverse fetal outcome, including abortions, IUGR or preterm labor may occur more frequently than anticipated. Our report strengthens the importance of awareness to this finding and focuses the need to consume properly cooked meat during pregnancy. © 2015 John Wiley & Sons, Ltd.     

Toward Active Community Environmental Policing: Potentials and Limits of a Catalytic Model

This paper offers a field tested community environmental policing model to address the pressing environmental management challenges of reducing e-waste burning in informal e-waste hubs, and enforcement against informal polluting industries more broadly. This is based on our intervention to reduce e-waste burning in a substantial informal e-waste hub in the West Bank, Palestine, a 45 km2 region in which an estimated 5–10 metric tonnes of cables are burnt daily, causing serious environmental and public health consequences. In analogous e-waste hubs in the global South, environmental management solutions have focused on economically attractive alternatives to replace cable burning or policies that integrate informal recyclers with formal e-waste management systems—achieving little success. Our paper describes a two-pronged intervention in Palestine’s e-waste hub, which reduced e-waste burning by 80% through a combination of economically competitive cable grinding services and an “active” community environmental policing initiative that lowered barriers to and successfully advocated for governmental policing of e-waste burning. Our discussion of this intervention addresses the community environmental policing literature, which has documented few successes stories of real improvements to the enforcement of environmental violations. We argue that existing strategies have relied on “passive” approaches comprised of monitoring and reporting environmental violations to advocate for change. Our strategy offers a template to improve outcomes through a more “active” approach, moving from monitoring environmental violations through understanding the rationale and dynamics of violators, identifying environmental policing barriers, and implementing a feasible and persuasive strategy to overcome them.     

Urban daily life routines and human exposure to environmental discomfort

This study suggests a shift in focus from studying environmental discomfort in urban strategic stations, from which average results for the city or specific results for selected sites are deduced, and from measuring environmental conditions in fixed monitoring stations to a study in which we monitor, with mobile portable sensors, the exposure of people to environmental sources of discomfort while performing their daily life activities. Significant variations in sense of discomfort were measured in this study, and almost half of this variability was found to be explained while four independent environmental variables were considered: air quality (concentrations of CO), noise level, climatic variables (thermal load), and social loads. The study conducted in the city of Tel Aviv, which suffers from hot, humid summers and cool winters, and noise levels that reach the average levels of 85 dB, and relatively lower levels of exposure to the other potential stressors. These levels of combined exposures result in moderate levels of discomfort for young, healthy people once they experience the more stressing environments in the city. It is shown also that noise from other people is the most salient source of discomfort in Tel Aviv. Levels of discomfort accumulate during the working hours, either due to the impact of social loads or noise, but the subjects showed good coping abilities that enabled them to recover in late afternoons. It seems that thermal load does not have immediate impact, but rather cumulative ones, mainly during transitional seasons when subjects are less adaptive to extreme changes in weather.     

Exposure of motorcycle,car and bus commuters to carbon monoxide on a main road in the Tel Aviv metropolitan area,Israel

Short-term personal exposure of passengers in different types of motor vehicles to carbon monoxide was investigated in an intensively used main road in Israel’s Tel Aviv metropolitan area. According to monitoring stations of the Ministry for Environmental Protection (MEP), concentrations of carbon monoxide (CO) along the road, at a height of 3 m above pedestrian level, in the Tel Aviv metropolitan area, are currently very low. However, these measurements do not reflect the actual exposure of commuters, which were the main objective of this study. Four vehicle types/travel modes were investigated: private cars with closed windows, private cars with open windows, motorcycles, and buses. The commuter CO average exposure was the accumulative exposure divided by the duration of the sampling taken along the route, for each type of vehicles. The results showed that commuters in cars with closed windows were exposed to the highest mean CO level, 27.2 ppm, for a period of 38 min; those in a car with open windows, to 19.7 ppm for 38 min; motorcycle riders, to 12.8 ppm, for 17 min; and bus users were exposed to the lowest mean pollution level, of only 3.6 ppm, for 25 min. Thus, CO values of 1 to 3 ppm, as measured at an MEP adjacent monitoring station, may indicate the exposure to CO pollution of area residents, but do not represent the actual exposure of commuters on the congested main road.